1. Field
The present disclosures relate generally to expandable medical implants for maintaining support of a body lumen, and more specifically, to a uniform stent having improved mechanical and post-deployment dynamic capabilities.
2. Description of the Related Art
Various embodiments of vascular implants; such as stents, thrombus filters, and heart valves, are used in their various embodiments for medical applications. Of these vascular devices, one of the leading candidates as a stent device and structural component is the radially expandable and slidably engaged stent as disclosed in commonly owned U.S. Pat. Nos. 6,033,436; 6,224,626; and 6,623,521; the disclosures of which are hereby incorporated by reference in their entirety. These radially expandable and slidably engaged stents offer the strength of prior expandable stents with the added improvements of low cross-section deliverability, less bulk material thickness, high resolution fitting, and shape customization such as hourglass-shape configurations.
Other radially expandable and slidably engaged stents; such as those disclosed in U.S. Pat. Nos. 5,797,951; 5,549,662; and 5,733,328; further describe the state of the art and their disclosures are hereby incorporated by reference.
Although promising candidates for use as implantable devices and device components, these known radially expandable and slidably engaged stents have mechanical and vasodynamic limitations of which the inventors of the present application set out to address. These limitations can be characterized as deployment related limitations, and limitations related to vasodynamic capabilities.
Deployment related limitations of prior art stents are herein described. Intravascular space; especially that of a patient in need of a vascular implant, is generally inconsistent and varies upon the individual with respect to curvature, plaque buildup and other luminary obstructions. Furthermore, the shape and structure of the stent may impact the rate and order that discrete areas of the stent deploy, e.g., expand. For instance, one portion of the stent may expand prior to a second portion of the stent. Such inconsistent and/or non-uniform deployment may render deployment and placement of prior art stents more difficult and less predictable.
Procedures are available to physicians such as balloon angioplasty, which aid in the reduction of plaque prior to stenting. However, even after such procedures, vascular characteristics remain patient delineated and largely inconsistent. Inconsistencies in vascular characteristics; such as the interference due to a luminary occlusion, require flexibility, distribution of material strength, and vascular adaptability of devices to be implanted.